After a strong period of ìAsset-Managementî (sale and resale of residential units) housing companies focus on ìProperty Managementî. Based on a survey of TU Darmstadt (supported by Aareon) with 304 housing companies in Germany (housing cooperatives or communal, investors and administrators of condominiums) the author conducted further research on the critical factors for success and the hurdles to success within selected housing companies. Here focus is on tenancy, as one of most critical core business processes. There are different ways to run this process. Housing companies differ significanctly in their strategies used to reduce vacancies due to changes in tenancy, as well as in the development and redevelopment of residential areas and existing units. Key indicators to measure the success of the tenancy process are rarely applied. For an optimization, individual parts of the process are isolated in order to provide possibilities to describe tune-ups. Tune-ups are defined as the means to accelerate the implementation of the customer requirements and help to reduce general administration expenses and to assure management decision. The author measures the current weaknesses and strengths of IT-solutions (Portfolio Management, Internet, time scheduling, Ö) and quantifies the benefits.